1. Field of the Invention
The present invention relates to an improvement of the cage position detecting apparatus for an elevator which is controlled by an operation of a computer.
2. Description of the Prior Arts
The detection of the cage position is indispensable for the operation of the elevator and is carried out by a floor selector.
Various floor selectors have been proposed. Recently, it has been considered to utilize the operation of a computer. In this system, floor pass switches are placed on each floor to indicate the present position of the cage by the addition and subtraction for the floors through which the cage is passed.
The cage position signals obtained by the floor selectors are used for indicating the cage position on the floors and in the cage and for the decision of the stopping of the cage.
When there is an erroneous input for the outputs of the floor pass switches, certain deviation is given between the operated cage position and the actual cage position, whereby the continued movement is not possible. There is a possibility to give an incorrect data for the cage position memorized by the operation, especially in the case of the service interruption. Even though the service interruption is released, it is impossible to carry out the normal operation. Thus, in such cases, the output of the floor selector is calibrated to the actual cage position. For example, when the output of the floor selector designates the final end floor (the top floor or the bottom floor), the cage is run to the final floor so as to be coincident the output with the cage position. It is also possible to be coincident the output with the cage position by actuating the floor selector in the condition of stopping the cage.
It is, however, difficult to prevent the increase of the costs caused by the consumption of excess electric power and the requirement of the complicated circuit.